Incomplete absorption reactions at high energy

Abstract

Abstract The total reaction cross section of high-energy nucleus–nucleus collision reflects the nuclear density profiles of the colliding nuclei and is a standard tool to investigate the size properties of short-lived unstable nuclei. This relies on the assumption that the nucleus–nucleus collision is strongly absorptive in the sense of an optical model. However, this property does not hold completely, while incomplete absorption occurs when the overlap density of two colliding nuclei is low enough. In this paper, we propose a way to quantify this incompleteness, i.e., the “blackness” of the total reaction cross section. The significance of this quantification is shown by taking an example of the total reaction cross sections of proton-rich C isotopes.